Many sources of fuel today contain some amount of ethanol, because of the oxygen content, which assists in reducing emissions. One fuel type commonly supplemented with ethanol is gasoline used in engines for machines such as vehicles, boats, planes, and other equipment. Ethanol has a natural affinity for water and if improperly stored, fuel comprising of ethanol-blended gasoline may absorb water potentially leading to phase separation. Phase separation occurs when the water present exceeds the amount that can be held by the ethanol. Once separated, the water in the fuel may freeze in fuel lines under freezing temperatures and lead to engine damages.
When phase separation occurs, there will be two or three distinct layers formed in the tank. Of these, the auto fuel will be the top layer, with a layer of water at the bottom. An intermediate layer, if present, will be an ethanol-water mixture, which will often be of a milky color.
Phase separation is temperature dependent. For example, an auto fuel with 10% ethanol (“E-10”) can hold approximately 0.05% water at 60° F., which amounts to about 3.8 teaspoons of water per gallon of fuel. When the temperature drops to 20° F., the fuel can only hold about 2.8 teaspoons of water.
Phase separation can happen in an underground or an aboveground storage tank, a vehicle tank, a boat tank, in any type of equipment tank, and even in the gas can in your garage.
The position of a phase separation interface relative to the fuel pick-up point will determine the observed effect of the phase separation. If the pick-up tube is in the water layer, most likely the engine will fail to start. If the engine is running and suddenly draws water you can have damage from thermal shock or hydro-lock. If the pick-up tube draws ethanol-water mixture or just ethanol, the engine will operate in an extreme lean condition, which can cause significant damage or even catastrophic failure. Even if the pick-up tube draws the gasoline, it will operate poorly due to lower octane that is the result of no longer having the ethanol in the fuel.
Ethanol separation can also affect fiberglass fuel tanks, especially as seen in boats but before the early 1990s. Ethanol can attack the materials from which the tanks are made.
Another additive previously used in gasolines, methyl teriary-butyl ether (“MTBE”), has effectively been displaced by ethanol. This is due to its carcinogenic nature and its ability to pollute ground water in the event of a fuel spill or leak.
Before MTBE or ethanol were used as fuel additives, a low-molecular weight alcohol such as methanol or ethanol water commonly used to eliminate phase separation. Now that ethanol is already in the fuel, the effectiveness of that former
It is therefore an unmet advantage to provide an effective phase separation reduction composition for use with ethanol-containing fuels.